What is the advantages/disadvantages of a sealed subwoofer box over a ported?

Question

I currently have a 10" mtx 5500 in a ported box, what is the difference between that and a sealed box?

Answer 1

http://spkrbox1.spaces.live.com

...an excerpt from my site....

Sealed Enclosures

Straightforward in design, the sealed box is nothing more than an airtight enclosure whose purpose is to enhance speaker performance. When a woofer is installed in one, the sound waves that emanate from the front of the speaker cone are separated from the rear-firing waves. This improves bass response, since opposing waves can cancel each other out when they aren't isolated. Superb damping, good power-handling capability, and simplicity of construction make the sealed-box enclosure an ideal candidate for a variety of installations. A sealed enclosure will be the smallest (for a given response shape) and will have good low frequency extension but may not have the best low frequency extension. If space is limited, this may be your best choice.

Vented Enclosures

Vented enclosures – also known as ported or bass-reflex systems – are more complex than sealed boxes, but the extra construction work required to install a vent has its rewards. Vented boxes are more efficient than their sealed counterparts, since they channel sound waves from the front and rear of the cone into the listening environment. Other virtues of the vented design include better reproduction of low bass, a reasonably flat response curve, and low distortion – provided the box is properly constructed. A vented enclosure will generally have a better low frequency extension for a given response shape (alignment) but would require a larger enclosure. If you made the enclosure as small as the sealed enclosure but ported it to gain the low frequency response, the output would deviate from the desired flat response.


Bandpass Enclosures

A bandpass enclosure can sound good and give you a flat response but most of the generic bandpass enclosures are not designed for a flat response. They are designed to impress you in the stores. This means that they are built to produce a large peak at some frequency near 60hz. These enclosures will work well with something like rap music but generally won't sound good with other types of music. If you use a bandpass enclosure, it should be designed specifically for your speakers.

If you're building your first system, I'd recommend a sealed enclosure. It is the simplest enclosure and will be the easiest to get right. A sealed enclosure only needs to be the right size and well sealed. Alright... Enough of my opinions.

Answer 2

Kyle M and odinragess are both right.

A sealed enclosure is easer to build and is more forgiving if you choose the wrong internal volume. The constant pressure inside the box prevents the cone from traveling to its furthest extremes (excursion), and so the cone returns to its neutral position faster. We hear this as "tighter" bass. Likewise, sealed enclosures are generally smaller that a ported enclosure for the same speaker. The problem with a sealed enclosure is that it shifts the speakers passband up in frequency. If, in free air, the speaker can pass, say, 30 hz at -3 dB (where output is down 50%), inside a sealed box that frequency will be shifted up to 55 hz or higher. In most popular music (rock, metal, hip-hop, most techno) this isn't a problem. But, if your playing alot of classical music, the music where the deepest bass usually happens (the fundemental tone of the lowest note on a pipe organ is 16 hz, which is below the range of human hearing) a sealed box is going to miss alot of that.

A ported box, on the other hand, is more complicated, and should only be built by someone who actually knows what they are doing (if you don't own a copy of Vance Dickeson's Loudspeaker Design Cookbook, you don't qualify). There are various alignments that exist, some of which will suit a particular driver, while others will not. There are no simple guidelines I can quote to tell you which to use, even knowing the T-S specs of your drivers. A ported box will generally have a lower power output, but that isn't universally so. A ported box will generally pass lower frequencies, but again, this isn't always the case.

Ultimately, there is no ultimate type of subwoofer. There is only a question of which subwoofer best suits your needs. The only way to know that for certain is for you to experiment, trying different alignments until you find what's right for you.

Answer 3

Sealed Subwoofer

Answer 4

No, you are ALL wrong. A ported box can have excellent response and sound quality is designed right, and the woofer is designed for it.

A ported box doesnt make a "deeper" bass note. That all depends on the "tuning" of the enclosure. Generally a sealed box usually "goes lower" If its big enough. If a ported box plays a freq. far below the tuning freq. the woofer will move out of control. Almost "oscillate" if you will. A sealed box will generally not experience this effect. But if the box is to small for the woofer it will sound terrible and not hit low frequencies.

Small boxes are "easier". Thats why theyll "sound better" to most people. Because most people dont know about car audio, and use wrong ported boxes, subs not made for ported boxes, wrong alignments, etc.

I like ported boxes because they offer increased volume and better efficiency. But, I am currently running a JL 8w6 in a sealed box, because of space.

Answer 5

Kyle M has the right idea. If you like tight bass and have the love for the feeling of bass, a sealed box is the best, especially if you run matching subs in 1 box, my prefference 2 12's in a single chamber box. I run 2 12's in a very tight 2.75 cubic litre box and the SPL boys in England are very impressed. My suggestion sealed and at least 15 mm thick preferrably thicker with a 1 inch fibre fill lining to soften the resonance

Answer 6

Look at the specs for the speaker. How much box room do you need for ported and how much do you need for sealed? Not all speakers work well ported. The TS-W302R handles 800 watts max. (150 watts nominal power) If this is the speaker it doesnt handle much power. Sealed would be better, less chance of blowing it. Need to watch how big of amp you put on them also. These are specs from website: Recommended Enclosure Use: 1.0 ~ 2.0 Cubic Feet But you get better specs in box with paperwork. honestly a prefab MDF box you can buy for about $60 and they come with about 1.1 Cubic Feet per speaker. And it fits perfect facing backwards in most trunks or hatchbacks. You gain 3 dB doing this.

Answer 7

my god you people are stupid. Youre completely wrong.

Sealed boxed dont allow for air to escape, thus there is a pressure change inside upon excursion, tending the subwoofer to return to normal. Basically that means you get better response with a sealed box, so your bass will be tighter, but less efficient dB wise.

Ported means air can go in and out, so there is no vacuum or high pressure force acting on the sub during excursion, giving it worse response, but better volume performance, and better deep bass (due to being able to move more air at lower frequencies with the same power).

ported boxes are usuall more complex and larger, while sealed are simple and smaller.

www.howstuffworks.com has some good info on the subject.

Answer 8

A ported box allows the pressure from the woofer to escape through one avenue. A sealed box compresses the air pressure in the box and gives a deeper, more rattling bass note. I have much experience with MTX and they have always recommended a sealed enclosure for their woofers. If you just have the one wofer you will be fine with the ported box because you usually need a bigger, well constructed box if it is sealed, which means it will be more expensive. I have put more money into enclousures than woofers.

Answer 9

advantages for a sealed box is it uses less air volume which means a smaller box and the bass is deeper,disadvantages compared to ported box , the ported box gives out louder bass but not as deep as a sealed, ported boxes require a little more air volume which means you will have a bigger box. one subwoofer in a ported box is just as loud as two subwoofers in a sealed box

Answer 10

If you like rock music loud. Go ported. for spl go mono signal. Usually stereo all around, but you could try mono on the subs. use equalizer always to tweak the sound. use crossover to direct signals to amps. check phase at speakers. point speakers at you. use right box size and port. most manufacturers supply box size for speaker. size type of car/truck can influence bass response. Buy the best amp and speakers you can. Some of my loudest great sounding systems used some fairly cheap equipment with ported boxes